As Hurricane Ian heads toward Florida, officials’ main concern is the threat of storm surge and catastrophic flooding, Florida. Gov. Ron DeSantis said Tuesday.

DeSantis reiterated that there is still time to prepare or evacuate.

About 2.5 million Floridians are under mandatory or voluntary evacuation orders, he said.

-ABC News’ Alex Faul

Tornado watches have been issued in Miami, Fort Lauderdale, West Palm Beach, Naples and Key West as Hurricane Ian approaches.

The watches are in effect until 5 p.m. Tuesday.

-ABC News’ Max Golembo

The forecast has shifted significantly east, now with landfall expected in the Tampa Bay area Wednesday night into early Thursday morning as a Category 3 hurricane.

This would mark Tampa Bay’s first direct hit from a major hurricane since 1921.

Slow-moving Ian is expected to drop more than 15 inches of rain from Tampa to Orlando.

Major flooding is possible in Orlando, Tampa and St. Petersburg.

-ABC News’ Max Golembo

Hurricane Ian made landfall over western Cuba early on Tuesday morning, the National Hurricane Center said.

“Satellite and radar data indicate that the center of Ian has made landfall just southwest of the town of La Coloma in the Pinar Del Rio Province of Cuba at 4:30 a.m.,” the center said.

Ian’s winds at landfall were estimated at a maximum of 125 mph, making the storm a Category 3 hurricane.

-ABC News’ Max Golembo

Federal Emergency Management Agency Administrator Deanne Criswell warned Tuesday, "Floridians are going to experience the impacts from the storm for a very long time."

"Our biggest concern as we wait for this storm to make landfall is storm surge," Criswell said. "In 2018, when Hurricane Michael impacted the Florida Panhandle, there were five recorded fatalities as a result of storm surge. So therefore, if people are told to evacuate by their local officials, please listen to them. The decision you choose to make may mean the difference between life and death."

President Joe Biden on Tuesday urged residents to "evacuate when ordered."

Biden said he spoke to the mayors of Tampa, St. Petersburg and Clearwater Tuesday morning and told them to "contact me directly" for "whatever they need."

Criswell said a search and rescue coordination group has been activated, including members from FEMA's urban search and rescue teams, the Coast Guard, the Department of Defense and the Department of the Interior.

The Red Cross has established 29 shelters and is prepared to open 60 more shelters if needed, she said.

Criswell stressed, "To those who may be watching at home, get ready and do not underestimate the potential that the storm can bring."